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The fast-developing information technology has imposed an urgent need for effective solutions to overcome the limitations of integration density in chips with smaller size but higher performance. van der Waals heterojunctions built with two-dimensional (2D) semiconductors have been widely studied due to their 2D nature, and their unique electrical and photoelectronic properties are quite attractive in realizing multifunctional devices toward multitask applications. In this work, black phosphorus (BP)/MoS2 heterojunctions have been used to build electronic devices with various functionalities. A p-n diode is achieved based on the vertically stacked BP/MoS2 heterojunction exhibiting an ideal factor of 1.59, whereas a laterally stacked BP/MoS2 heterojunction is implemented to fabricate a photodetector that shows a photodetection responsivity of 2000 mA/W at a wavelength of 1300 nm. Furthermore, a ternary inverter has been realized using a BP field-effect transistor in-series with a lateral BP/MoS2 heterojunction. Such results have unambiguously demonstrated the superiority of BP/MoS2 heterojunction in realizing multiple functionalities and have offered a new pathway for the design and engineering of future circuitry and device integration based on novel 2D semiconductors.

The fast-developing information technology has imposed urgent need for effective solutions to overcome the increasing power density in further scaled electronic devices and systems. The tunnel fiel...

TiO2 compact layer (c-TiO2) is generally applied for high-efficiencies perovskite solar cells (MPSCs), but it shows a relatively low electron mobility, which may restrict some performance of the MPSCs. Herein, we demonstrated SnO2 compact layer (c-SnO2), which prepared by spray pyrolysis using a solution of dibutyltin bisacetylacetonate in ethanol, could be an excellent alternative compact layer for efficient hole-conductor-free printable MPSCs. The best device with such a c-SnO2 has achieved an efficiency of 13.77%, which is very comparable to that obtained by the device based on c-TiO2. Furthermore, the device with c-SnO2 showed less pronounced hysteresis effect, probably because of the higher electron mobility of SnO2 and less charge accumulation at the interfaces. The simple preparation process and improved hysteretic behavior pave the way for industrialization of PSCs.

A compact-layer-free, hole-conductor-free, fully printable mesoscopic perovskite solar cell presents a power conversion efficiency of over 13%, which is comparable to that of the device with a TiO2 compact layer. The different wettability of the perovskite precursor solution on the surface of FTO and TiO2 possesses a significant effect on realizing efficient mesoscopic perovskite solar cell. This result shows a promising future in printable solar cells by further simplifying the fabrication process and lowering the preparation costs.

To meet the challenge of continuously increasing global energy demands, organic-inorganic halide based perovskite solar cells (PSCs) have garnered great attention from the photovoltaic research community for their low cost and high efficiency. The efficiency of perovskite-based mesoscopic solar cells increases rapidly, from 3.8% in 2009 to 22.1% in 2016. N-type metal-oxide electron transport layer, as one of the important components in mesoscopic PSCs (MPSCs), acts as not only a scaffold layer for the growth of perovskite crystals, but also a layer to supply transfer pathways for electrons injected from perovskites. In this review, we discussed recent published reports of MPSCs with the focus on n-type metal-oxide electron transport layer in MPSCs. The scaffold materials, scaffold nanostructure, and scaffold/perovskite interface engineering are considered, and the effects of these modifications of scaffolds on the performance of MPSCs are summarized in this review.

A printing process for the fabrication of perovskite solar cells (PSCs) exhibits promising future application in the photovoltaic industry due to its low-cost and eco-friendly preparation. In mesoscopic carbon-based PSCs, however, compared to conventional ones, the hole-transport-layer-free PSCs often lead to inefficient hole extraction. Here, we used liquid metal (LM, Galinstan) as an interface modifier material in combination with a carbon electrode. Considering the high conductivity and room-temperature fluidity, it is found that LMs are superior in improving hole extraction and, more importantly, LMs tend to be reserved at the interface between ZrO2 and carbon for enhancing the contact property. Correspondingly, the carrier transfer resistance was decreased at the carbon/perovskite interface. As optimized content, the triple mesoscopic PSCs based on mixed-cation perovskite with a power conversion efficiency of 13.51% was achieved, involving a 26% increase compared to those without LMs. This work opens...